One of the major purposes of skin cosmetics is to improve the outward, especially facial, appearance. Typically foundations are used to enhance features, or mask perceived imperfections in them. As foundations are typically applied prior to other color cosmetics, they provide a uniform base of color and coverage which improve the overall appearance of make-up. Characteristics considered by consumers when choosing a foundation fall into three general areas; look (or appearance both upon application and after wear), feel (e.g., ease of application and the feel of the "made up" area), and wear (resistance to water, oil, abrasion, etc.). These foundations are generally available in the form of liquid, semiliquid or cream suspensions, emulsions, gels, as well as pressed powders or anhydrous oil and wax compositions.
The skin cosmetic art has long sought to provide foundations that alter the perception of the skin, especially the skin of the face. For example, foundations are used over the entire face to mask perceived imperfections in skin texture, pigmentation or vascularization. Foundations present special challenges to the skilled artisan as they cover larger areas of the skin, thus defects are more apparent, making it more difficult to provide a good look. Unlike other color cosmetics, they are typically applied with the hand, and their presence is more visibly apparent than other skin cosmetics, such as moisturizers. As a result, the foundation must provide an exceptionally even covering, without looking unnatural, and must be easy and pleasant feeling to apply.
Usually the consumer chooses foundations that provide the desired skin color. These needs are often met by selecting the properly pigmented foundation to provide the desired effect.
The skin cosmetic industry strives to produce long wearing, good looking foundations to hide perceived imperfections in facial skin. These foundations are prepared from a number of known materials. However, the commonly used materials present problems in that they are not impervious to the effects of the water or skin secretions, including sweat or sebaceous oils and thus they do not wear well. Such penetrability provides for "bleeding" of the foundation, and its concomitant uneven look when worn for a long period of time, "smudging" or abrasion of the foundation, and the like. Thus a foundation must be substantial enough to withstand these common signs of wear.
As an example of this effort to improve the wear characteristics, the art has considered formulating simple pigment mixtures of volatile solvents with waxes and gelling agents. These compositions are not easy to pleasant to apply, and may use costly solvents, making the foundation more expensive. While such formulations may provide water resistant films, employing volatile organic solvents in products has provided compositions that lacked spreadability. Packaging problems occurred because the loss of solvent in the product before application produced a hard, unusable material. In addition, these pigmented mixtures have not been successful because they require careful application to avoid heavy coverage.
To avoid these stability and application problems, conventional pigmented oil-in-water emulsions were developed. They are cheaper, and tend to be relatively stable. The pigmented oil-in-water emulsion is one of the more popular types of foundations on the market today. The pigmented oil-in-water emulsion lends itself to variation in pigment level and oil level to give different degrees of color coverage and emolliency. However, these foundations have several drawbacks: First, because such a foundation is not impenetrable to oil and water, partial `fading` or `bleeding` of the color during wear still occurs. Second, while these foundations may be easier to apply, they can still lack blendability. Lack of blendability is a considerable problem as the cosmetic cannot be touched-up, and typically the make-up must be removed and applied anew. Third, because the external phase is aqueous, these foundations can produce a cold and wet feeling upon application. Fourth, they can be difficult to spread evenly on the skin, particularly when oily substances (for example, previously applied moisturizers, sebum, etc.) are present on the skin during application.
Conventional foundations do not produce coverage which is sufficiently water-resistant, oil-resistant, and friction-resistant. Those in the art have sought to improve foundations' wear properties, such as adhesion to the skin, resistance to abrasion, water, and skin oils, by providing a foundation that forms a film. Often this "film" is a wax or polymer, that is packaged with solvent, as described above. Upon evaporation the foundation leaves a paste or continuous film on the face. This foundation typically feels different during application and wear then conventional skin cosmetics. This difference in feel has resulted in poor consumer acceptance of these products.
A more recent strategy employed by the art to address this problem is the coating of pigments in skin cosmetics. It is thought that such coated pigments may stay in suspension better, and provide color stability in the package. Examples of hydrophobically coated pigments and hydrophilically treated pigments are known. Incorporation of these pigments into an cosmetic may improve wear characteristics. These products do not form a fully integrated film, but have slightly improved wear because the coating on the pigment can adhere to the skin. For example, U.S. Pat. No. 5,260,052 discloses the use of polymer coatings for this purpose.
The most recent development in the art is the advent of "film forming" skin cosmetics. The goal of a "film forming" skin cosmetic is to provide the better looking, longer lasting benefits compared to the conventional skin cosmetic, while avoiding a film that appears or feels heavy or drying to the skin. Attempts to address the problems of the conventional skin cosmetic have led to previously unforeseen problems, such as giving an undesirable "plaster-like" look to the skin, the skin cosmetic "peeling up" from the face, cracking, peeling, or flaking after wear. Abrasion by the hands or clothes has often exacerbated this cracking, peeling or flaking.
Should these problems be overcome, these skin cosmetics offer challenges to consumer acceptance in the feel or the application of the skin cosmetic. Because consumers have become accustomed to the dry, smooth feel of the conventional non-film forming skin cosmetics, the different feel and often different application techniques of the film forming skin cosmetics are not readily received by consumers. For example, because these film forming skin cosmetics thicken rapidly while forming the film, they may be difficult to apply and then feel tacky at the end of application, or if applied too slowly they may provide a streaky or uneven appearance, as new applications of the cosmetic do not blend well with previously applied and partially dried skin cosmetic. Additionally, the film forming skin cosmetics may not spread as well because they may be forming the film or thickening during application.
As a result of these challenges, the art has avoided liquid, semi-liquid or cream formulations of film forming skin cosmetics, such as foundations, because they are applied with the hands. As an example, the undesirable thickening or tackiness would be most noticeable in the application of a foundation. In addition, any tackiness or thickening would exacerbate the problems of blending the foundation.
However, the challenges remain for foundations applied or manipulated by the hands, especially when used over larger areas. For example, external phase polymers in skin cosmetics feel tacky during application and polymer coated pigments can lack the "evenness" desired, when applied to a large area. In addition, where the polymers used are hydrophobic, they are also difficult to wash off, without special aids, such as cleansing creams and the like. Each of these approaches provide new undesirable application and "feel" drawbacks. Of course, improvements found in formulating these polymers would be desirable.
The art has also sought new polymers in an effort to avoid these drawbacks. The art teaches several film forming polymers, which are said to be safe for skin:
One such film former is a water dispersible acrylic, manufactured by various suppliers under various names, such as DERMACRYL LT, (Acrylates/Octylacrylamide Copolymer) from National Starch. This polymer is water soluble, and thus is expected to provide ease in formulation. However, soluble polymers in general not provide the same "skin cosmetic" feel as non-filming skin cosmetics, and tends to be sticky during drying. While consumers may tolerate this in products where extended wear is the overriding concern, but such products generally do not enjoy wide consumer acceptance in skin cosmetics for this reason.
Polyester AQs, are water dispersible sulfopolyester. Eastman's U.S. Pat. No. 5,260,052 describing pigment dispersions using a sulfopolyester as a pigment coating, with Eastman's U.S. Pat. No. 5,226,322 describing a composition comprising an oil-in-water emulsion of polyester resin for skin cosmetic purposes with AQ. Several of these resins exist, for example, AQ29D, AQ35S, AQ38D, AQ38S, AQ48S, AQ55S, and are available from Eastman Chemicals. They are marketed either as solid or dispersed polymers. Typically, skin cosmetics formulated from these polymer coated pigments of from oil-in-water emulsions containing these polymers provide skin cosmetics that are tacky and are not generally used or widely recommended where the foundation is applied with the hands.
Several other polymers exist in the art that are touted as being useful for skin cosmetics, but lack the preferred characteristics, such as low tackiness, good skin adhesion and the like.
It would be advantageous to provide a film forming skin cosmetic that is stable, easy and pleasant feeling to apply, provides a good looking cosmetic, and also provides good wear characteristics. Yet the cosmetic must be easily removed with soap and water.
Thus the desired film forming foundation provides the proper "feel" in that it lacks tackiness or stickiness, does not thicken too rapidly during application, but is smooth and dry, while adhering to the skin. The desired film forming foundation also provides a "good look" even coverage, is blendable and adheres to the skin, while not appearing heavy. The desired film forming foundation is not compromised by skin secretions or water, does not "bleed" with wear, does not crack, smudge, abrade or peel.